The effect of subjective value of the reinforcer (RSv) on performance in a sentence-construction, verbal conditioning task was examined. Sixty undergraduate males were randomly assigned to positive or negative reinforcement groups in which they were reinforced (E said "Good" and "Hmm," respectively) following sentences beginning with designated pronouns. After each sentence, 5s rated the pleasantness of the reinforcer or of E's silence. Awareness of the pronoun-reinforcement contingency was assessed by four separate procedures: a commonly used postconditioning interview, written "thoughts about the experiment," a simple recognition question, and a new card-sort technique. Using the most defensible criterion of awareness, only aware 5s who rated the reinforcer as more pleasant than silence showed significant performance change. Performance of unaware 5s was unaffected by the value of RSv. It was concluded that the effect of RSv on performance was mediated by awareness of the correct response-reinforcement contingency.